This invention relates generally to a detection circuit for an electronic timepiece and more particularly to a detection circuit used to provide an indication when the power source is initially connected to the timepiece circuits. This indication assures that the battery is properly connected and the timekeeping circuits are functioning. In prior art circuits, an electrostatic capacitance is connected in series with a resistor. When the power source is applied, a current flows to charge the electrostatic capacitance through the resistance. At that time, it is determined whether the power source is connected or not connected by detecting an electric voltage signal at the connection point between the capacitance and the resistor.
However, the circuits of the prior art have the following defficiencies. Namely, when chattering is caused at the contact of the battery when the battery is applied, the output signal of electric voltage at the connection point between the capacitance and the resistor differs from the normal signal which should be produced when the power source is applied to the circuit without chatter. Thus, it is not always possible to properly detect whether the power source is or is not properly applied.
What is needed is a detection circuit for an electronic timepiece which provides a reliable indication of application of the power source even should chattering occur or the power be temporarily interrupted.